Continued investigations on the identification of the hormonal and nutritional factors that regulate the synthesis and degradation of enzymes synthesizing cholesterol and fatty acids in mammalian liver are proposed. We also propose a similar investigation on the control of the synthesis and degradation of serum lipoproteins. These studies will then be followed with ones on the mechanisms by which hormones control the rates of synthesis of lipogenic enzymes and serum lipoproteins. Isolated cells, tissue cultures and cell-free systems will be used in these investigations to determine whether the action of the hormone is at the translational or transcriptional site. We will then attempt to establish and detailed biochemical mechanisms of hormonal control of the rates of synthesis and degradation of lipogenic enzymes and serum lipoproteins. A second phase of the proposed investigations will be concerned with the sites and mechanisms of transport of cholesterol within the artery. Attempts will be made to identify the sites of binding and the order of transfer of cholesterol in arterial cells. A companion investigation will be concerned with the enzymatic synthesis of polyisoprenoid compounds in membranes in plaque and nonplaque regions of arteries. Particular attention will be paid to the possibility to abnormal membrane formation in cells of plaque regions.